Some differences were noted across treatment modalities in the perceived benefits of treatment. Clients in outpatient drug-free programs were less likely to report that treatment improved their health than those in inpatient, residential, or methadone programs (53 percent compared with 70 percent). Also, clients in methadone programs were less likely than those in the other three types of programs to report that treatment helped with emotional, nervous, or mental health problems (45 percent compared with 60 percent) or with planning their future (34 percent compared with 60 percent). However, more striking than these differences were the similarities across treatment modalities. Also of note was the consistent positive association of the perceived benefits in almost all domains with abstinence and reduction in substance use. It should be noted, however, that the SROS data were based on self-reports, not objective measures, and that the study was a naturalistic one, not a randomized clinical trial. Therefore, results should be interpreted with caution.